e39 headlights

[Scamp's Walker]

Being a novice e39 owner, I am a little in the dark (ha ha) about "angel eyes" etc. The only thing I am disappointed with, after 2 months of ownership are the headlights on dip beam. The width and length of the beam are fantastic, however they don't seem to be too bright! Is it merely a case of upgrading the bulbs to xenon aftermarket bulbs (if so which are the best ones? I have been recommended the autobulbsdirect 6500 ones!). The covers appear to be pretty clean and clear but am not sure what to clean them with without scratching them. The other option, of course, is to upgrade the light units themselves to the later options but I am not sure if that will make that much difference when considering the cost. Anybody "shed any light" on my predicament?